Spores are known to form from aerobic Bacilli, anaerobic Clostridia , selected sarcinae and a few actinomycetes. Spores resemble certain plant seeds in that they do not carry out any metabolic reactions. In this regard they are especially suited to withstand severe environmental stress and are known to survive prolonged exposures to heat, drying, radiation and toxic chemicals. These properties make spores especially difficult to kill in environments, like living tissue or objects which come in contact with living tissue, which would be adversely effected by extreme conditions.
Fungi, viruses and vegetative cells of pathogenic bacteria are sterilized within minutes at 70 degrees Celsius; many spores are sterilized at 100 degrees Celsius. However, the spores of some saprophytes can survive boiling for hours. Heat is presently the most commonly used means to insure sterilization of spores.
The outer coat of spores is made of a keratin-like protein which comprises as much as 80% of the total protein of the spore. It is this protein coat which is responsible for the resistance of spores to chemical sterilizing agents. The spore stage of the microbial life cycle is characterized by metabolic dormancy and resistance to environmental factors that would destroy the microbe in its vegetative stage.
Germination of bacterial endospores and fungal spores is associated with increased metabolism and decreased resistance to heat and chemical reactants. For germination to occur, the spore must sense that the environment is adequate to support vegetation and reproduction. Simple alpha amino acids may stimulate spore germination.
The present invention provides an improved enzymatic method for killing or inactivating spores.